Thrift: Support for explicit Python module declaration.

Summary:
Previously, Thrift used the name of the .thrift file as the python module name.
This wasn't very flexible.  Now the python module can be explicitly declared.
Also, there was no need for t_py_generator to inherit from t_oop_generator.

Reviewed By: mcslee

Test Plan:
cd test/py/explicit_module
./runtest.sh

Revert Plan: ok


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@665234 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/thrift.vim b/thrift.vim
index c421cf3..1e2dad1 100644
--- a/thrift.vim
+++ b/thrift.vim
@@ -30,7 +30,7 @@
 syn match thriftNumber "-\=\<\d\+\>" contained
 
 " Keywords
-syn keyword thriftKeyword namespace cpp_namespace java_package php_namespace ruby_namespace perl_package
+syn keyword thriftKeyword namespace cpp_namespace java_package php_namespace ruby_namespace py_module perl_package
 syn keyword thriftKeyword xsd_all xsd_optional xsd_nillable xsd_namespace xsd_attrs
 syn keyword thriftKeyword include cpp_include cpp_type const optional required
 syn keyword thriftBasicTypes void bool byte i16 i32 i64 double string binary